Chapter 12 Images:

Figure 12.1. Figure 12.1. Mr. Grainger's "Cholera Map of the Metropolis. 1849. Exhibited in the Registration Districts" (details). There were four districts south of the River Thames that might have interested Snow-#25, St. Saviour, Southwark; #26, St. Olave, Southwark; #27, Bermondsey; #28, St. George, Southwark; and #29, Newington. The dotted lines indicated where cross-sections were taken for showing elevation above the high-water mark on the River Thames. Places with "bad ventilation," "no drainage," "open sewer," and "overcrowding" were also marked on the map (GBH, Report on Cholera, 1848-49, appendix B, opposite 200).

Figure 12.2. Figure 12.2. A portion of the "Chart Shewing the Progress of the Spasmodic Cholera." Solid reddish lines (shaded in this figure) indicated the movement of cholera from southeast Asia to western Europe and England and then on to the eastern seaboard of Canada and the United States (Brigham, Treatise on Epidemic Cholera, frontispiece).

Figure 12.4. Edmund Cooper's map of the Broad Street cholera epidemic made for the Metropolitan Commission of Sewers, September 1854. Inset: the Broad Street pump and surrounding addresses. Cooper designated each affected house by a large solid bar, and the cholera deaths occurring in each house by thin lines.

Figure 12.6. Detail from Snow's spot map of the Golden Square outbreak showing area enclosed within the Voronoi network diagram. Snow's original dotted line to denote equidistance between the Broad Street pump and the nearest alternative pump for procuring water has been replaced by a solid line for legibility. Fold lines and tear in original (adapted from CIC, between 106 and 07).

Figure 12.7. (left) Snow's spot map, detail of area around the Broad Street pump (from MCC2). (right) Snow's spot map, detail of area around the Broad Street pump. The finely dotted Voronoi line is in the lower half; the symbol for the Broad Street pump-circle around black dot-has been repositioned to its correct location opposite no. 40 Broad Street (from CIC, between 106 and 107).

Figure 12.8. The General Board of Health map used by CIC, with Whitehead's "cholera area" indicated by a circle (CIC, between 96 and 97).